Process for the preparation of substituted phenylalanines

ABSTRACT

Intermediates and synthetic processes for the preparation of substituted phenylalanine-based compounds (e.g., of Formula I) are disclosed:

This application claims priority to U.S. provisional application No.60/754,785, filed Dec. 29, 2005, the entirety of which is incorporatedherein by reference.

1. FIELD OF THE INVENTION

This invention relates to synthetic processes used to make substitutedphenylalanine-based compounds.

2. BACKGROUND

The neurotransmitter serotonin [5-hydroxytryptamine (5-HT)] is involvedin multiple central nervous facets of mood control and in regulatingsleep, anxiety, alcoholism, drug abuse, food intake, and sexualbehavior. In peripheral tissues, serotonin is reportedly implicated inthe regulation of vascular tone, gut motility, primary hemostasis, andcell-mediated immune responses. Walther, D. J., et al., Science 299:76(2003).

The enzyme tryptophan hydroxylase (TPH) catalyzes the rate limiting stepof the biosynthesis of serotonin. Two isoforms of TPH have beenreported: TPH1, which is expressed in the periphery, primarily in thegastrointestinal (GI) tract, and; TPH2, which is expressed in the brain.Id. The isoform TPH1 is encoded by the tph1 gene; TPH2 is encoded by thetph2 gene. Id.

Mice genetically deficient for the tph1 gene (“knockout mice”) have beenreported. In one case, the mice reportedly expressed normal amounts ofserotonin in classical serotonergic brain regions, but largely lackedserotonin in the periphery. Id. In another, the knockout mice exhibitedabnormal cardiac activity, which was attributed to a lack of peripheralserotonin. Côté, F., et al., PNAS 100(23):13525-13530 (2003).

Because serotonin is involved in so many biochemical processes, drugsthat affect serotonin levels are often attended by adverse effects.Thus, a need exists for new methods of affecting serotonin levels.

3. SUMMARY OF THE INVENTION

This invention encompasses the preparation of compounds of formula I:

and pharmaceutically acceptable salts and solvates thereof, wherein thevarious substituents are defined herein. When administered to mammals,preferred compounds of this formula inhibit TPH (e.g., TPH1), and may beuseful in the treatment of various diseases and disorders.

This invention is also directed to various intermediates that are usefulin the synthesis of compounds of formula I.

4. DETAILED DESCRIPTION

This invention is based on the discovery of a novel process that can beused to efficiently prepare compounds of formula I. When administered tomammals, preferred compounds of formula I inhibit peripheral TPH, andmay be used in the treatment of various diseases and disorders,including disorders of the GI tract. See generally, U.S. patentapplication No. 60/754,955, filed Dec. 29, 2005.

4.1. Definitions

Unless otherwise indicated, the term “alkenyl” means a straight chain,branched and/or cyclic hydrocarbon having from 2 to 20 (e.g., 2 to 10 or2 to 6) carbon atoms, and including at least one carbon-carbon doublebond. Representative alkenyl moieties include vinyl, allyl, 1-butenyl,2-butenyl, isobutylenyl, 1-pentenyl, 2-pentenyl, 3-methyl-1-butenyl,2-methyl-2-butenyl, 2,3-dimethyl-2-butenyl, 1-hexenyl, 2-hexenyl,3-hexenyl, 1-heptenyl, 2-heptenyl, 3-heptenyl, 1-octenyl, 2-octenyl,3-octenyl, 1-nonenyl, 2-nonenyl, 3-nonenyl, 1-decenyl, 2-decenyl and3-decenyl.

Unless otherwise indicated, the term “alkyl” means a straight chain,branched and/or cyclic (“cycloalkyl”) hydrocarbon having from 1 to 20(e.g., 1 to 10 or 1 to 4) carbon atoms. Alkyl moieties having from 1 to4 carbons are referred to as “lower alkyl.” Examples of alkyl groupsinclude, but are not limited to, methyl, ethyl, propyl, isopropyl,n-butyl, t-butyl, isobutyl, pentyl, hexyl, isohexyl, heptyl,4,4-dimethylpentyl, octyl, 2,2,4-trimethylpentyl, nonyl, decyl, undecyland dodecyl. Cycloalkyl moieties may be monocyclic or multicyclic, andexamples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, andadamantyl. Additional examples of alkyl moieties have linear, branchedand/or cyclic portions (e.g., 1-ethyl-4-methyl-cyclohexyl). The term“alkyl” includes saturated hydrocarbons as well as alkenyl and alkynylmoieties.

Unless otherwise indicated, the term “alkylaryl” or “alkyl-aryl” meansan alkyl moiety bound to an aryl moiety.

Unless otherwise indicated, the term “alkylheteroaryl” or“alkyl-heteroaryl” means an alkyl moiety bound to a heteroaryl moiety.

Unless otherwise indicated, the term “alkylheterocycle” or“alkyl-heterocycle” means an alkyl moiety bound to a heterocycle moiety.

Unless otherwise indicated, the term “alkynyl” means a straight chain,branched or cyclic hydrocarbon having from 2 to 20 (e.g., 2 to 20 or 2to 6) carbon atoms, and including at least one carbon-carbon triplebond. Representative alkynyl moieties include acetylenyl, propynyl,1-butynyl, 2-butynyl, 1-pentynyl, 2-pentynyl, 3-methyl-1-butynyl,4-pentynyl, 1-hexynyl, 2-hexynyl, 5-hexynyl, 1-heptynyl, 2-heptynyl,6-heptynyl, 1-octynyl, 2-octynyl, 7-octynyl, 1-nonynyl, 2-nonynyl,8-nonynyl, 1-decynyl, 2-decynyl and 9-decynyl.

Unless otherwise indicated, the term “alkoxy” means an —O-alkyl group.Examples of alkoxy groups include, but are not limited to, —OCH₃,—OCH₂CH₃, —O(CH₂)₂CH₃, —O(CH₂)₃CH₃, —O(CH₂)₄CH₃, and —O(CH₂)₅CH₃.

Unless otherwise indicated, the term “aryl” means an aromatic ring or anaromatic or partially aromatic ring system composed of carbon andhydrogen atoms. An aryl moiety may comprise multiple rings bound orfused together. Examples of aryl moieties include, but are not limitedto, anthracenyl, azulenyl, biphenyl, fluorenyl, indan, indenyl,naphthyl, phenanthrenyl, phenyl, 1,2,3,4-tetrahydro-naphthalene, andtolyl.

Unless otherwise indicated, the term “arylalkyl” or “aryl-alkyl” meansan aryl moiety bound to an alkyl moiety.

Unless otherwise indicated, the terms “halogen” and “halo” encompassfluorine, chlorine, bromine, and iodine.

Unless otherwise indicated, the term “heteroalkyl” refers to an alkylmoiety in which at least one of its carbon atoms has been replaced witha heteroatom (e.g., N, O or S).

Unless otherwise indicated, the term “heteroaryl” means an aryl moietywherein at least one of its carbon atoms has been replaced with aheteroatom (e.g., N, O or S). Examples include, but are not limited to,acridinyl, benzimidazolyl, benzofuranyl, benzoisothiazolyl,benzoisoxazolyl, benzoquinazolinyl, benzothiazolyl, benzoxazolyl, furyl,imidazolyl, indolyl, isothiazolyl, isoxazolyl, oxadiazolyl, oxazolyl,phthalazinyl, pyrazinyl, pyrazolyl, pyridazinyl, pyridyl, pyrimidinyl,pyrimidyl, pyrrolyl, quinazolinyl, quinolinyl, tetrazolyl, thiazolyl,and triazinyl.

Unless otherwise indicated, the term “heteroarylalkyl” or“heteroaryl-alkyl” means a heteroaryl moiety bound to an alkyl moiety.

Unless otherwise indicated, the term “heterocycle” refers to anaromatic, partially aromatic or non-aromatic monocyclic or polycyclicring or ring system comprised of carbon, hydrogen and at least oneheteroatom (e.g., N, O or S). A heterocycle may comprise multiple (i.e.,two or more) rings fused or bound together. Heterocycles includeheteroaryls. Examples include, but are not limited to,benzo[1,3]dioxolyl, 2,3-dihydro-benzo[1,4]dioxinyl, cinnolinyl, furanyl,hydantoinyl, morpholinyl, oxetanyl, oxiranyl, piperazinyl, piperidinyl,pyrrolidinonyl, pyrrolidinyl, tetrahydrofuranyl, tetrahydropyranyl,tetrahydropyridinyl, tetrahydropyrimidinyl, tetrahydrothiophenyl,tetrahydrothiopyranyl and valerolactamyl.

Unless otherwise indicated, the term “heterocyclealkyl” or“heterocycle-alkyl” refers to a heterocycle moiety bound to an alkylmoiety.

Unless otherwise indicated, the term “heterocycloalkyl” refers to anon-aromatic heterocycle.

Unless otherwise indicated, the term “heterocycloalkylalkyl” or“heterocycloalkyl-alkyl” refers to a heterocycloalkyl moiety bound to analkyl moiety.

Unless otherwise indicated, the term “pharmaceutically acceptable salts”refers to salts prepared from pharmaceutically acceptable non-toxicacids or bases including inorganic acids and bases and organic acids andbases. Suitable pharmaceutically acceptable base addition salts include,but are not limited to, metallic salts made from aluminum, calcium,lithium, magnesium, potassium, sodium and zinc or organic salts madefrom lysine, N,N′-dibenzylethylenediamine, chloroprocaine, choline,diethanolamine, ethylenediamine, meglumine (N-methylglucamine) andprocaine. Suitable non-toxic acids include, but are not limited to,inorganic and organic acids such as acetic, alginic, anthranilic,benzenesulfonic, benzoic, camphorsulfonic, citric, ethenesulfonic,formic, fumaric, furoic, galacturonic, gluconic, glucuronic, glutamic,glycolic, hydrobromic, hydrochloric, isethionic, lactic, maleic, malic,mandelic, methanesulfonic, mucic, nitric, pamoic, pantothenic,phenylacetic, phosphoric, propionic, salicylic, stearic, succinic,sulfanilic, sulfuric, tartaric acid, and p-toluenesulfonic acid.Specific non-toxic acids include hydrochloric, hydrobromic, phosphoric,sulfuric, and methanesulfonic acids. Examples of specific salts thusinclude hydrochloride and mesylate salts. Others are well known in theart. See, e.g., Remington's Pharmaceutical Sciences (18th ed., MackPublishing, Easton Pa.: 1990) and Remington: The Science and Practice ofPharmacy (19th ed., Mack Publishing, Easton Pa.: 1995).

Unless otherwise indicated, the term “protecting group” or “protectivegroup,” when used to refer to part of a molecule subjected to a chemicalreaction, means a chemical moiety that is not reactive under theconditions of that chemical reaction, and which may be removed toprovide a moiety that is reactive under those conditions. Protectinggroups are well known in the art. See, e.g., Greene, T. W. and Wuts, P.G. M., Protective Groups in Organic Synthesis (3^(rd) ed., John Wiley &Sons: 1999); Larock, R. C., Comprehensive Organic Transformations(2^(nd) ed., John Wiley & Sons: 1999).

Unless otherwise indicated, the term “pseudohalogen” refers to apolyatomic anion that resembles a halide ion in its acid-base,substitution, and redox chemistry, generally has low basicity, and formsa free radical under atom transfer radical polymerization conditions.Examples of pseudohalogens include azide ions, cyanide, cyanate,thiocyanate, thiosulfate, sulfonates, and sulfonyl halides.

Unless otherwise indicated, the term “stereoisomeric mixture”encompasses racemic mixtures as well as stereomerically enrichedmixtures (e.g., R/S=30/70, 35/65, 40/60, 45/55, 55/45, 60/40, 65/35 and70/30).

Unless otherwise indicated, the term “stereomerically pure” means acomposition that comprises one stereoisomer of a compound and issubstantially free of other stereoisomers of that compound. For example,a stereomerically pure composition of a compound having one stereocenterwill be substantially free of the opposite stereoisomer of the compound.A stereomerically pure composition of a compound having twostereocenters will be substantially free of other diastereomers of thecompound. A typical stereomerically pure compound comprises greater thanabout 80% by weight of one stereoisomer of the compound and less thanabout 20% by weight of other stereoisomers of the compound, greater thanabout 90% by weight of one stereoisomer of the compound and less thanabout 10% by weight of the other stereoisomers of the compound, greaterthan about 95% by weight of one stereoisomer of the compound and lessthan about 5% by weight of the other stereoisomers of the compound,greater than about 97% by weight of one stereoisomer of the compound andless than about 3% by weight of the other stereoisomers of the compound,or greater than about 99% by weight of one stereoisomer of the compoundand less than about 1% by weight of the other stereoisomers of thecompound.

Unless otherwise indicated, the term “substituted,” when used todescribe a chemical structure or moiety, refers to a derivative of thatstructure or moiety wherein one or more of its hydrogen atoms issubstituted with a chemical moiety or functional group such as, but notlimited to, alcohol, aldehylde, alkoxy, alkanoyloxy, alkoxycarbonyl,alkenyl, alkyl (e.g., methyl, ethyl, propyl, t-butyl), alkynyl,alkylcarbonyloxy (—OC(O)alkyl), amide (—C(O)NH-alkyl- or-alkylNHC(O)alkyl), amidinyl (—C(NH)NH-alkyl or —C(NR)NH₂), amine(primary, secondary and tertiary such as alkylamino, arylamino,arylalkylamino), aroyl, aryl, aryloxy, azo, carbamoyl (—NHC(O)O-alkyl-or —OC(O)NH-alkyl), carbamyl (e.g., CONH₂, as well as CONH-alkyl,CONH-aryl, and CONH-arylalkyl), carbonyl, carboxyl, carboxylic acid,carboxylic acid anhydride, carboxylic acid chloride, cyano, ester,epoxide, ether (e.g., methoxy, ethoxy), guanidino, halo, haloalkyl(e.g., —CCl₃, —CF₃, —C(CF₃)₃), heteroalkyl, hemiacetal, imine (primaryand secondary), isocyanate, isothiocyanate, ketone, nitrile, nitro, oxo,phosphodiester, sulfide, sulfonamido (e.g., SO₂NH₂), sulfone, sulfonyl(including alkylsulfonyl, arylsulfonyl and arylalkylsulfonyl),sulfoxide, thiol (e.g., sulfhydryl, thioether) and urea(—NHCONH-alkyl-).

Unless otherwise indicated, the term “include” has the same meaning as“include, but are not limited to,” and the term “includes” has the samemeaning as “includes, but is not limited to.” Similarly, the term “suchas” has the same meaning as the term “such as, but not limited to.”

Unless otherwise indicated, one or more adjectives immediately precedinga series of nouns is to be construed as applying to each of the nouns.For example, the phrase “optionally substituted alky, aryl, orheteroaryl” has the same meaning as “optionally substituted alky,optionally substituted aryl, or optionally substituted heteroaryl.”

It should be noted that a chemical moiety that forms part of a largercompound may be described herein using a name commonly accorded it whenit exists as a single molecule or a name commonly accorded its radical.For example, the terms “pyridine” and “pyridyl” are accorded the samemeaning when used to describe a moiety attached to other chemicalmoieties. Thus, the two phrases “XOH, wherein X is pyridyl” and “XOH,wherein X is pyridine” are accorded the same meaning, and encompass thecompounds pyridin-2-ol, pyridin-3-ol and pyridin-4-ol.

It should also be noted that if the stereochemistry of a structure or aportion of a structure is not indicated with, for example, bold ordashed lines, the structure or the portion of the structure is to beinterpreted as encompassing all stereoisomers of it. Moreover, any atomshown in a drawing with unsatisfied valences is assumed to be attachedto enough hydrogen atoms to satisfy the valences. In addition, chemicalbonds depicted with one solid line parallel to one dashed line encompassboth single and double (e.g., aromatic) bonds, if valences permit.

4.2. Methods of Synthesis

This invention encompasses the preparation of compounds of formula I:

and pharmaceutically acceptable salts and solvates thereof, wherein thevarious substituents are defined herein. The invention is particularlydirected to the synthesis of compounds of formulae I(b), I(c), I(d) andI(e):

In one aspect of the invention, the synthesis of such compounds isachieved via a compound of formula I(a):

One embodiment of the invention encompasses a method of preparing acompound of formula I(a), which comprises contacting a compound offormula II:

with a compound of formula III:

under conditions sufficient for the formation of the compound of formulaI(a), wherein:

A is optionally substituted cycloalkyl, aryl, or heterocycle;

X is O, S, or NR₆;

Y₁ is halogen or pseudohalogen;

one of Z₁, Z₂, Z₃, and Z₄ is a carbon atom attached to the adjacentoptionally substituted phenyl moiety, and the others are eachindependently CR₇ or N;

P₁ is R₁ or a protecting group;

P₂ is a protecting group;

P₃ is OR₂, SR₂, NR₉R₁₀, NHNHR₉, or a protecting group;

R₁ is hydrogen or optionally substituted alkyl, alkyl-aryl,alkyl-heterocycle, aryl, or heterocycle;

R₂ is hydrogen or optionally substituted alkyl, alkyl-aryl,alkyl-heterocycle, aryl, or heterocycle;

R₃ is hydrogen, cyano, or optionally substituted alkyl or aryl;

R₄ is hydrogen, cyano, or optionally substituted alkyl or aryl;

each R₅ is independently hydrogen, cyano, nitro, halogen, OR₈, NR₉R₁₀,or optionally substituted alkyl, alkyl-aryl or alkyl-heterocycle;

R₆ is hydrogen or optionally substituted alkyl or aryl;

each R₇ is independently hydrogen, cyano, nitro, halogen, OR₈, NR₉R₁₀,or optionally substituted alkyl, alkyl-aryl or alkyl-heterocycle;

each R₈ is independently hydrogen or optionally substituted alkyl,alkyl-aryl or alkyl-heterocycle;

each R₉ is independently hydrogen, a protecting group, or optionallysubstituted alkyl, alkyl-aryl or alkyl-heterocycle;

each R₁₀ is independently hydrogen, a protecting group, or optionallysubstituted alkyl, alkyl-aryl or alkyl-heterocycle; and

n is 1-4.

In one embodiment, P₃ is OR₂. In another, R₂ is hydrogen. In another, Z₁is CR₇. In another, R₇ is NR₉R₁₀. In another, R₉ is hydrogen. Inanother, R₁₀ is hydrogen. In another, Z₂ is N. In another, Z₃ is acarbon atom attached to the adjacent optionally substituted phenylmoiety. In another, Z₄ is CR₇. In another, R₇ is hydrogen. In another, nis 1. In another, R₅ is hydrogen. In another, X is O. In another, R₃ ishydrogen. In another, R₄ is optionally substituted alkyl. In another, R₄is —CF₃. In another, A is optionally substituted biphenyl.

In a particular embodiment, the compound of formula II is of formulaII(a):

wherein: R₁₁ is independently hydrogen, cyano, nitro, halogen, OR₈,NR₉R₁₀, or optionally substituted alkyl, alkyl-aryl oralkyl-heterocycle; each R₁₂ is independently hydrogen, cyano, nitro,halogen, OR₈, NR₉R₁₀, or optionally substituted alkyl, alkyl-aryl oralkyl-heterocycle; m is 1-5; and p is 1-4. In another, the compound offormula II(a) is of formula II(b):

In another embodiment, the compound of formula III is of formula III(a):

In another, the compound of formula III(a) is of formula III(b):

In a particular embodiment, the compound of formula II is prepared bycontacting a compound of formula IV:

with a compound of formula V:

under conditions sufficient for the formation of the compound of formulaII, wherein: A₁ is optionally substituted cycloalkyl, aryl, orheterocycle; A₂ is optionally substituted cycloalkyl, aryl, orheterocycle; Y₂ is halogen or pseudohalogen; and each R is independentlyhydrogen, optionally substituted alkyl, alkyl-aryl, alkyl-heterocycle,aryl, or heterocycle, or are taken together with the oxygen atoms towhich they are attached to provide a cyclic dioxaborolane.

In one embodiment, A₁ is optionally substituted phenyl. In another, A₁is anisole. In another, A₂ is optionally substituted phenyl. In another,A₂ is phenyl. In another, R₃ is hydrogen. In another, R₄ is optionallysubstituted alkyl. In another, R₄ is —CF₃. In another, X is O.

In a particular embodiment, the compound of formula IV is of formulaIV(a):

wherein: each R₁₁ is independently hydrogen, cyano, nitro, halogen, OR₈,NR₉R₁₀, or optionally substituted alkyl, alkyl-aryl oralkyl-heterocycle; and m is 1-5. In another, the compound of formulaIV(a) is of formula IV(b):

In another, the compound of formula V is of formula V(a):

wherein: each R₁₂ is independently hydrogen, cyano, nitro, halogen, OR₈,NR₉R₁₀, or optionally substituted alkyl, alkyl-aryl oralkyl-heterocycle; and p is 1-4. In one embodiment, the compound offormula V(a) is of formula V(b):

In a particular embodiment, the compound of formula III(a) is preparedby contacting a compound of formula VI:

with a compound of formula VII:

under conditions sufficient for the formation of the compound of formulaIII, wherein: Y₃ is halogen or pseudohalogen; and each R′ isindependently hydrogen or optionally substituted alkyl, alkyl-aryl,alkyl-heterocycle, aryl, or heterocycle, or are taken together with theoxygen atoms to which they are attached to provide a cyclicdioxaborolane.

In one embodiment, n is 1. In another, R₅ is hydrogen. In another, Z₁ isCR₇. In another, R₇ is NR₉R₁₀. In another, R₉ is hydrogen. In another,R₁₀ is hydrogen. In another, Z₂ is N. In another, Z₃ is a carbon atomattached to the adjacent optionally substituted phenyl moiety. Inanother, Z₄ is CR₇. In another, R₇ is hydrogen.

In a particular embodiment, the compound of formula VI is of formulaVI(a):

In another, the compound of formula VI(a) is of formula VI(b):

In another, the compound of formula VI(a) is of formula VI(c):

In another, the compound of formula VII is of formula VII(a):

In another, the compound of formula VII(a) is of formula VII(b):

One embodiment of the invention comprises deprotecting the compound offormula I(a) to provide a compound of formula I:

wherein: R₁ is hydrogen or optionally substituted alkyl, alkyl-aryl,alkyl-heterocycle, aryl, or heterocycle. In a particular embodiment, thecompound of formula I is of formula I(b):

wherein: each R₁₁ is independently hydrogen, cyano, nitro, halogen, OR₈,NR₉R₁₀, or optionally substituted alkyl, alkyl-aryl oralkyl-heterocycle; each R₁₂ is independently hydrogen, cyano, nitro,halogen, OR₈, NR₉R₁₀, or optionally substituted alkyl, alkyl-aryl oralkyl-heterocycle; m is 1-5; and p is 1-4.

In one embodiment, the compound of formula I(b) is of formula I(c), I(d)or I(e):

Certain embodiments of the invention can be understood with reference toScheme 1:

In this approach, compounds of general formulae VI and VII are coupledunder conditions suitable for the formation of a compound of formula III(e.g., contact with a transition metal catalyst, a base, and a solventor solvent mixture with water), moieties of which may be deprotected ifappropriate. The compound of formula III is then coupled with a compoundof formula II under conditions sufficient to provide a compound offormula I(a) (e.g., nucleophilic substitution conditions), which isdeprotected (e.g., by hydrolysis under acidic or basic conditions) toafford the compound of general formula I.

A more specific adaptation of the approach shown in Scheme 1 is providedbelow. Scheme 2(a) shows the preparation of two intermediate compounds:

Conditions sufficient for the formation of the compound of formula II(a)include the use of a transition metal catalyst, a base, and a solvent orsolvent mixture with water. The intermediate compounds are coupled asshown below in Scheme 2(b), to provide a compound that is deprotected toprovide the final product:

Various reaction conditions may be used in this approach to obtain thedesired product. As those skilled in the art will immediately recognize,preferred reaction conditions may depend on the specific compoundsinvolved. In one embodiment of the invention, Y₁ is Cl. In another, Y₂is Br. In another, Y₃ is Cl. In another, R is hydrogen. In another, R′is hydrogen. In another, both R′ are taken together with the oxygenatoms to which they are attached to provide4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl.

In another embodiment, each protecting group is independentlyaryl-alkyl, heteroaryl-alkyl, or —C(O)R₁₃, wherein R₁₃ is alkyl,aryl-alkyl, aryl, heterocycle, alkoxy, aryloxy, or aryl-alkoxy. Examplesof protecting groups include benzyl, diphenylmethyl, trityl, Cbz, Boc,Fmoc, methoxycarbonyl, ethoxycarbonyl, and pthalimido.

In addition to the various synthetic methods disclosed herein, thisinvention encompasses novel compounds that can be used to preparecompounds of formula I.

Examples include compounds of the formula:

and salts and solvates thereof, wherein: P₁ is R₁, —C(O)R₁₃, oroptionally substituted alkyl, alkyl-aryl, alkyl-heterocycle, aryl, orheterocycle; P₂ is —C(O)R₁₃ or optionally substituted alkyl, alkyl-aryl,alkyl-heterocycle, aryl, or heterocycle; R₁ is hydrogen or optionallysubstituted alkyl, alkyl-aryl, alkyl-heterocycle, aryl, or heterocycle;and each R₁₃ is independently alkyl, aryl-alkyl, aryl, heterocycle,alkoxy, aryloxy, or aryl-alkoxy.

In one embodiment, P₁ is hydrogen. In another, P₂ is benzyl,diphenylmethyl, trityl, Cbz, Boc, Fmoc, methoxycarbonyl, ethoxycarbonyl,or pthalimido. A particular compound is of the formula:

The invention also encompasses compounds of the formula:

and salts and solvates thereof, wherein P₁ is R₁, —C(O)R₁₃, oroptionally substituted alkyl, alkyl-aryl, alkyl-heterocycle, aryl, orheterocycle; P₂ is —C(O)R₁₃ or optionally substituted alkyl, alkyl-aryl,alkyl-heterocycle, aryl, or heterocycle; R₁ is hydrogen or optionallysubstituted alkyl, alkyl-aryl, alkyl-heterocycle, aryl, or heterocycle;and each R₁₃ is independently alkyl, aryl-alkyl, aryl, heterocycle,alkoxy, aryloxy, or aryl-alkoxy.

In one embodiment, P₁ is hydrogen. In another, P₂ is benzyl,diphenylmethyl, trityl, Cbz, Boc, Fmoc, methoxycarbonyl, ethoxycarbonyl,or pthalimido. A particular compound is of the formula:

This invention also encompasses compounds of the formula:

and salts and solvates thereof.

5. EXAMPLES

The following non-limiting examples describe the synthesis of(S)-2-amino-3-(4-(2-amino-6-((R)-2,2,2-trifluoro-1-(3′-methoxybiphenyl-4-yl)ethoxy)pyrimidin-4-yl)phenyl)-propanoicacid.

Generally, intermediate compounds 3 and 8 are first prepared, as shownbelow in Schemes 3(a) and (b):

An alternate synthesis of compound 8 is shown in Scheme 3(c):

The intermediates are then coupled as shown below in Scheme 3(d):

In the following examples, yields of various reactions are reported on amolar basis. Unless otherwise indicated, reagents are commerciallyavailable and may be purchased from Sigma-Aldrich Company, Inc.(Milwaukee, Wis., USA).

5.1. Preparation of (R)-1-(4-Bromophenyl)-2,2,2-trifluoroethanol (2)

This compound was prepared based on a literature procedure (Ohkuma, etal. J. Am. Chem. Soc., 1998, 120, 13529-13530). To a 1 L high pressurevessel was charged 4-bromo-trifluoroacetophenone (1, WilmingtonPharmaTech, Delaware, 100.0 g, 395 mmol), potassium tert-butoxide (1 Msolution in 2-methyl-2-propanol, 5.0 ml, 10.0 mmol, 0.025 eq), andcatalyst [(trans)-RuCl₂[(R)-Xyl-P-Phos][(R)-DIAPEN] (Johnson Matthey,New Jersey, 200 mg, 0.16 mmol, 0.04% mol). The mixture was dissolved inanhydrous 2-propanol (175 ml) and the entire vessel was purged withargon by 3 vacuum-thaw cycles. The reaction mixture was then purged withhydrogen by 3 vacuum-thaw cycles. The reaction was carried out under 60psi hydrogen atmosphere. After 24 h of stirring and no more hydrogenconsumption, the reaction was deemed complete by GC-MS analysis (no morestarting ketone). The contents of the reaction vessel were transferredto a round bottom flask with MeOH rinsing (3×20 ml), and concentratedunder reduced pressure until no more solvent was distilling off. Theresulting orange-brown oil was then dissolved in heptane (1000 ml) andwashed with water (2×100 ml), brine (100 ml) and dried over sodiumsulfate. To the dried organic layer was added Darco® activated charcoal(20 g) and Hyflo® Super Cel (20 g) and the mixture was heated at 70° C.for 1 h. The mixture was filtered hot to give a light yellow solution.The filtrate was concentrated under reduced pressure with heating(˜50-60° C.) until no more solvent was distilling. The resulting yellowoil was dissolved in 60° C. warm heptane (350 ml) and allowed to stirwhile cooling. As the temperature cooled to rt., white solid began toprecipitate. After 4 h of stirring, the solids were filtered and driedto give the titled product (63.5 g, 63%, >99% ee) as a white powder.m.p.: 56.7° C. [α]=−30.1 (c1.09, ethanol). GC-MS (CI): MH⁺=255.8. ¹H NMR(CDCl₃) δ 7.58 (m, 2H), 7.42 (d, J=8.3 Hz, 2H), 5.00 (m, 1H), 2.62 (d,J=4.3 Hz, 1H). ¹³CNMR (CDCl₃): δ 133.2, 132.2, 129.5, 125.7, 124.3 (q,J=282 Hz), 72.6 (q, J=32 Hz). ¹⁹F NMR (CDCl₃): δ-78.5 (d, J=5.6 Hz).

5.2. (S)-1-(4-Bromophenyl)-2,2,2-trifluoroethanol

Using a procedure similar to the above example, the titled compound wasprepared using catalyst [(trans)-RuCl₂[(S)-Xyl-P-Phos][(S)-DIAPEN](Johnson Matthey, New Jersey).

5.3. (R)-2,2,2-Trifluoro-1-(p-tolyl)ethanol

Similarly, 2,2,2-trifluoro-1-(p-tolyl)ethanone was hydrogenated usingcatalyst [(trans)-RuCl₂[(R)-Xyl-P-Phos][(R)-DIAPEN] to give the titledcompound. m.p.: 44.2° C.

¹H NMR (CDCl₃): δ 7.38 (d, J=6.0 Hz, 2H), 7.25 (d, J=6.0 Hz, 2H), 5.00(dq, J₁=6.6 Hz, J₂=3.3 Hz, 1H), 2.49 (d, J=3.8 Hz, 1H), 2.42 (s, 3H).

5.4. (S)-2,2,2-Trifluoro-1-(p-tolyl)ethanol

Similarly, the titled compound was prepared using catalyst[(trans)-RuCl₂[(S)-Xyl-P-Phos][(S)-DIAPEN].

5.5. (R)-2,2,2-Trifluoro-1-(3′-methoxybiphenyl-4-yl)ethanol (3)

To a stirred solution of (R)-1-(4-bromophenyl)-2,2,2-trifluoroethanol(2, 69 g, 0.27 mol, >99% ee), 3-methoxy phenylboronic acid (Matrix, 51g, 0.34 mol, 97% purity), and bis(triphenylphosphine)palladium(II)dichloride (0.95 g, 0.5% mol) in ethanol (560 ml) was added a solutionof potassium carbonate (112 g, 0.81 mol) in water (140 ml) undernitrogen. The resulting mixture was heated at 75° C. for 1 h and deemedcomplete by GC-MS or TLC. After reaction mixture was cooled to 40° C.,it was filtered through a pad of Celite, washed with methanol (3×100ml). The filtrate was diluted with 100 ml of water and concentrated. Theresulting syrup was dissolved in 700 ml of ethyl acetate and washed with1 N sodium hydroxide (2×100 ml), water (2×100 ml) and brine (1×100 ml).The organic layer was heated with activated carbon (14 g) and HyfloSuper Cel (14 g) at 60° C. for 1 h. This mixture was filtered hot andwashed with ethyl acetate (100 ml) and then concentrated to a syrup.This syrup was immediately dissolved in 1% ethyl acetate/heptane (700ml) and stirred for 4 h. The resulting slurry was filtered and dried togive the titled compound as a white crystalline solid (3, 68 g, 89%yield, >99% ee)

Alternative crystallization method: The crude product syrup/solid (10 g)was dissolved in MTBE (10 ml) and diluted with heptane (200 ml). Thesolution was concentrated to about 70 ml under reduced pressure. Thismixture was stirred at rt overnight and the resulting slurry wasfiltered and dried to give the title compound (3, 8.8 g) as a whitecrystalline solid. m.p.: 107.6° C. [α]=−31.85 (c 1.067, ethanol). LC-MS(ESI): MH⁺=283.1.

¹H NMR (CDCl₃): δ 7.66 (m, 2H), 7.56 (d, J=8.2 Hz, 2H), 7.42 (t, J=7.8Hz, 2H), 7.20 (m, 1H), 7.14 (m, 1H), 6.95 (m, 1H), 5.82 (q, J=6.6 Hz,1H), 3.85 (s, 3H), 2.63 (br s, 1H). ¹³C NMR (CDCl₃): δ 160.3, 142.6,142.2, 133.5, 130.3, 128.3, 127.8, 124.8 (q, J=282 Hz), 120.1, 113.4,113.3, 73.0 (q, J=32 Hz), 55.7. ¹⁹F NMR (CDCl₃): δ −78.3 (d, J=6.4 Hz).

Residual palladium: 11 ppm. Anal. Calcd for C₁₅H₁₃F₃O₂: C, 63.83; H,4.64. Found: C, 63.78; H, 4.60.

5.6. (R)-2,2,2-Trifluoro-1-(3′-methoxybiphenyl-4-yl)ethanol (3)

A 22-L, round-bottom flask equipped with a mechanical stirrer, athermocouple attached to a temperature controller, and a condenser witha nitrogen line was charged with compound 2 (1.00 kg, 1 wt, 3.92 mol)and ethanol (4.5 L, 4.5 vol). The mixture was sparged with nitrogen for10 min and (Ph₃P)₂PdCl₂ (12.6 g, 0.0126 wt, Strem) was added. Followingadditional sparging with nitrogen, a solution of K₂CO₃ (1.63 kg, 3equiv) in water (2 vol) was added. The mixture was heated to 75° C.under nitrogen and then approximately 20% of a solution of 3-methoxyphenylboronic acid (715 g, 4.70 mol, 1.2 equiv, Usun) in ethanol (4.5vol) was added via a peristaltic pump. After 20 min, an in-processcontrol (IPC) sample was taken and showed that the boronic acid had beenconsumed. This process was repeated until all of the boronic acid wasadded. After stirring for a further 20 min, HPLC analysis showed thatthe reaction was complete. The heat was switched off and at 69° C.,water (3.6 vol) was added. The reaction mixture was then filtered at 50°C. through a pad of celite (Celpure P300, 0.15 wt., Sigma) and thefilter cake was washed with methanol (2×2.5 vol). The filtrate wasconcentrated under reduced pressure at 40-45° C. to 5 vol. The slurrywas then transferred to a separatory funnel and MTBE (10 vol) was added.The mixture was then washed with a 50% solution of sodium hydroxide (0.6vol). After stirring, the layers were separated and the aqueous phasewas extracted with MTBE (1.5 vol). The organic extracts were combinedand washed with water (1 vol) followed by 20% aqueous sodium chloride (1vol) to provide 11.9 volumes of organic product solution. The solutionwas transferred to a reactor, treated with a slurry of Darco G-60 (0.3wt) in MTBE (1 vol) and heated to 50° C. After 90 min, the mixture wasfiltered through a pad of Celpure P300 (0.15 wt) and washed with MTBE(2×3 vol).

The filtrate (14.8 vol) was transferred to a reactor and distilled undervacuum at 45° C. to remove MTBE. The filtrate was reduced to 6.7 volumesover 2.5 hours and then heptane (3.15 vol) was added. The solution wasfurther distilled at 50° C. to 6.7 vol over 1 h and then additionalheptane (3.15 vol) was added. The solution was concentrated to 6.7 volat 55° C. over 1.5 h and then heptane was added (3.15 vol).Precipitation was observed immediately and the distillation wascontinued under vacuum at 60° C. After 2.5 h, the distillation wasstopped (7 vol remaining), the heat was switched off and the batch wascooled overnight to ambient temperature. The batch was filtered at 24°C. and washed with heptane (1.5 vol). The solids were dried at roomtemperature under vacuum over the weekend to provide 799.7 g of 3 as awhite solid [72% yield, >99% (AUC)].

5.7. (R)-2,2,2-Trifluoro-1-(3′-fluorobiphenyl-4-yl)ethanol

Similar to the above procedure, the title compound was prepared from(R)-1-(4-bromophenyl)-2,2,2-trifluoroethanol (2) and3-fluorophenylboronic acid. ¹H NMR (CDCl₃): δ 7.62(d, J=6.0 Hz, 2H),7.56 (d, J=6.3 Hz, 2H), 7.42 (m, 2H), 7.28 (m, 1H), 7.06 (m, 1H), 5.82(q, J=5.1 Hz, 1H).

5.8. (S)-Methyl2-(tert-butoxycarbonylamino)-3-(4-(trifluoromethylsulfonyloxy)phenyl)propanoate(5)

This compound was prepared based on a literature procedure (Shieh, etal. J. Org. Chem., 1992, 57, 379-381). To a solution of Boc-Tyr-OMe (4,Bachem, California, 100 g, 0.34 mol) and N-methylmorpholine (51 g, 1.5eq) in dichloromethane (1000 ml) was added triflic anhydride (100 g,1.05 eq) over 2 h at −5 to −15° C. The resulting red solution wasstirred at −10° C. for 10 min. HPLC analysis showed completedisappearance of starting material. The reaction was quenched with 10%citric acid (500 ml). The organic layer was washed with 10% citric acid(500 ml) followed by water (500 ml). The resulting light pink solutionwas concentrated under reduced pressure to 200 ml. This was diluted withacetonitrile (600 ml) and further concentrated to a 200 g solution. Thissolution was used in the next step without further purification.Estimated yield is 98% by stripping a sample to dryness to give a lowmelting pale yellow solid. LC-MS (ESI): MH⁺=428.0, MNH₄ ⁺=445.0. ¹H NMR(CDCl₃) δ 7.16 (m, 4H), 4.95 (d, J=7.1 Hz, 1H), 4.53 (m, 1H), 3.64 (s,3H), 3.10 (dd, J₁=5.7 Hz, J₂=13.8 Hz, 1H), 2.97 (dd, J₁=6.3 Hz, J₂=13.6Hz, 1H), 1.34 (s, 9H). ¹³C NMR (CDCl₃) δ 172.3, 155.4, 149.0, 137.4,131.5, 121.7, 119.1 (q, J=321 Hz), 80.54, 54.62, 52.7, 38.3, 28.6. ¹⁹FNMR (CDCl₃) δ −73.4.

5.9.(S)-2-(Tert-butoxycarbonylamino)-3-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)propanoicacid (7)

This ester compound 6 was prepared based on a literature procedure(Firooznia, et al., Tetrahedron Lett., 1999, 40, 213-216).Bis(pinacolato)diboron (90 g, 1.1 eq), potassium acetate (63 g, 2 eq),tricyclohexylphosphine (2.3 g, 2.5% mol), and palladium acetate (0.72 g,1 mol %) were mixed in acetonitrile (950 ml) and the resulting mixturestirred at r.t. for 5 min. The above triflate (5) solution (190 g, 0.32mol) was added and the resulting mixture was heated at 80° C. for 1 hand cooled. HPLC showed complete consumption of the starting material.The reaction mixture was quenched with aqueous potassium bicarbonatesolution (57 g in 475 ml water) and resulting mixture was stirred atr.t. for 30 min. The mixture was filtered through a pad of 20μ celluloseto remove palladium black. A sample of the organic layer wasconcentrated and purified by column chromatography (gradient: 1:10 to1:4 ethyl acetate/hexanes) to give the ester compound 6 as a clear oil.LC-MS (ESI): MH⁺=406.2, MNH₄ ⁺=423.2, M₂H⁺=811.5, M₂NH₄ ⁺=428.5. ¹H NMR(CDCl₃) δ 7.76 (d, J=8.1 Hz, 2H), 7.15 (d, J=7.6 Hz, 2H), 4.96 (d, J=7.3Hz, 1H), 4.60 (m, 1H), 3.72 (s, 3H), 3.13 (m, 2H), 1.44 (s, 9H), 1.36(s, 12H).

The above organic layer of 6 was stirred with aqueous lithium hydroxidesolution (23 g in 500 ml water) at r.t. for 30 min. The pH of theresulting slurry was adjusted to about 10 with 6 N hydrochloric acid andfiltered. The cake was washed with water (200 ml). Acetonitrile wasremoved from the filtrate under reduced pressure to give an aqueousslurry (950 ml, additional water was added during distillation). Theslurry was filtered through a pad of 20μ cellulose and washed with water(200 ml). The filtrate was washed with MTBE (500 ml) and rediluted with700 ml MTBE. The mixture was acidified to pH about 4.5 with 6 Nhydrochloric acid. The organic layer was washed with water (500 ml) andconcentrated under reduced pressure to the titled product (7) as a brownoil (206 g, 95% yield based on estimated purity by NMR). The crudeproduct was used directly in the following step. LC-MS (ESI): MH⁺=392.2,MNH₄ ⁺=409.2, M₂H⁺=783.4, M₂NH₄ ⁺=800.4. ¹H NMR (CDCl₃) δ 7.95 (br s,1H), 7.76 (d, J=7.8 Hz, 2H), 7.21 (d, J=7.6 Hz, 2H), 5.03 (d, J=7.8 Hz,1H), 4.62 (m, 1H), 3.18 (m, 2H), 1.43 (s, 9H), 1.35 (s, 12H). ¹³C NMR(CDCl₃) δ 175.8, 155.7, 139.7, 135.4, 129.2, 84.2, 80.5, 54.5, 38.3,28.7, 25.2.

Compound 7 can optionally isolated by crystallization. Thus, the aboveMTBE solution of 7 can be dried with anhydrous Na₂SO₄ and concentratedto about 1.0 vol under vacuum. Heptane (2.5 vol) was added andconcentrated to about 1.5 vol under vacuum. Heptane (4.2 vol) was addedslowly at 36˜42° C. followed by cooling slowly to 5˜10° C. The resultingslurry is filtered, washed by heptane, and dried under vacuum at 20-30°C. to give the product 7 in about 76% yield.

5.10. Alternative Crystallization of(S)-2-(Tert-butoxycarbonylamino)-3-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)propanoicacid (7)

A 1 L jacketed three-necked round bottom flask with mechanical stirrer,rubber septum with temperature probe, and gas bubbler was charged with100 ml of an ethanol solution containing 50.88 g 7. The solution was setstirring under nitrogen, diluted with 35 ml ethanol, then with 50 ml2-propanol, and was heated to ˜60° C. Then 250 ml water were added toreach the cloudy point and the turbid solution was held at ˜60° C. for75 min followed by cooling to ˜10° C. over ˜1.5 hrs. After 45 min, themixture was biphasic and was diluted with an additional 30 ml2-propanol. The mixture was stirred under nitrogen at 10° C. overnightand the resulting white fine suspension was filtered. The collectedsolids were washed with 100 ml 9:1 water:2-propanol and were dried invacuo at ˜50-60° C. to give 39.88 g 7 as a chalky white powder (78%recovery). The solid was in the filtrate was filtered and dried toafford 4.51 g of a pale yellow granular solid. HPLC suggested thismaterial was mostly the boronic acid 12.

5.11.(S)-3-(4-(2-Amino-6-chloropyrimidin-4-yl)phenyl)-2-(tert-butoxycarbonylamino)propanoicacid (8)

The above crude compound 7 (0.32 mol) was dissolved in ethanol (800 ml)and resulting solution was concentrated under reduced pressure to about700 ml and diluted with ethanol (1300 ml). To this solution was added2-amino-4,6-dichloropyrimidine (74 g, 1.4 eq),bis(triphenylphosphine)palladium(II) dichloride (2.3 g, 1 mol %), andaqueous potassium bicarbonate solution (97 g, 3 eq, 380 ml water). Thismixture was heated at 75-80° C. for 2 h, at which time HPLC analysisshowed complete consumption of the starting material. Ethanol wasremoved from the filtrate under reduced pressure to give an aqueousslurry (600 ml, additional water was added during distillation). Theslurry was filtered and washed with 200 ml water. The cake was dried at50° C. under vacuum to give recovered 2-amino-4,6-dichloropyrimidine asa tan solid (30 g, 41% of original charge). ¹H NMR (DMSO-d₆) δ 7.58 (brs, 2H), 6.84 (s, 1H). ¹³C NMR (DMSO-d₆) δ 162.8, 160.9, 107.5. Thefiltrate was washed with ethyl acetate (400 ml) and diluted with 3:1THF/MTBE (600 ml). The mixture was acidified to pH about 3.5. Theorganic layer was washed with brine (300 ml) and concentrated to givethe crude product 8 as a red oil (180 g). This oil was redissolved inTHF (300 ml), polish-filtered, and washed with THF (100 ml). Thefiltrate was diluted with isopropanol (400 ml) and the mixture wasdistilled atmospherically to about 300 ml. More isopropanol (400 ml) wasadded and distillation continued until the volume reached about 500 ml.The mixture was then cooled over 1 h to 45° C. and held for 2 h beforeit was cooled to r.t. over 1 h. After 1 h hold, the slurry was filtered,washed with isopropanol (150 ml), and dried at 50° C. under vacuum togive the product 8 as a light pink solid (46.2 g, 37% yield fromBoc-Tyr-OMe, 4). Purity: 93.4% by HPLC. Chiral purity: >99% ee. Chiralanalysis was performed on the corresponding methyl ester derivative,which was prepared using trimethylsilyldiazomethane. An analytical puresample was obtained by column chromatography (gradient 1:20 to 1:10methanol/dichloromethane). LC-MS (ESI) MH⁺=393.1,MH⁺+acetonitrile=434.1, M₂H⁺=785.3. ¹H NMR (DMSO-d₆) δ 12.60 (s, 1H),8.02 (d, J=8.3 Hz, 2H), 7.38 (d, J=8.1 Hz, 2H), 7.23 (s, 1H), 7.13 (brs, 2H), 3.09 (dd, J₁=4.4 Hz, J₂=13.5 Hz, 1H), 2.91 (dd, J₁=10.5 Hz,J₂=13.8 Hz, 1H), 1.32 (s, 9H). ¹³C NMR (DMSO-d₆) δ 173.4, 165.8, 163.5,161.0, 155.4, 141.4, 134.0, 129.4, 126.8, 104.4, 78.0, 54.8, 36.2, 28.1.Anal. Calcd for C₁₈H₂₁ClN₄O₄: C, 55.03; H, 5.39; N, 14.26. Found: C,54.76; H, 5.65; N, 14.09.

HPLC analysis of the above mother liquor against an standard solution ofcompound 8 showed additional 38 g product 8 (30% yield from Boc-Tyr-OMe,4). Product 8 can be partially recovered by further concentration of themother liquor to give a total yield of 60% from Boc-Tyr-OMe, 4.

5.12.(S)-3-(4-(2-Amino-6-chloropyrimidin-4-yl)phenyl)-2-(tert-butoxycarbonylamino)propanoicacid (8)

A 22-L, round-bottom flask equipped with a mechanical stirrer, athermocouple attached to a temperature controller, and a condenser witha nitrogen line was charged with compound 7 (850 g, 1 wt, 2.17 mol),2-amino-4,6-dichloropyrimidine (712.3 g, 2 equiv, Usun), and ethanol(13.6 L, 16 vol). The slurry was sparged with nitrogen for 10 min; then(Ph₃)₂PdCl₂ (18.3 g, 0.021 wt, Strem) was added and nitrogen spargingwas continued for 10 min. A solution of potassium bicarbonate (783 g,3.6 equiv) in water (3.2 L, 3.7 vol) was then charged to the reactorwhereupon gas evolution was observed. The mixture was heated to 75° C.for a total of 11.5 h and then cooled to 45° C. overnight. HPLC analysisafter 9.5 h at 75° C. indicated that there were about 3.0% of 7remaining (by conversion). The reaction was cooled to 45° C. and stirredovernight whereupon HPLC analysis indicated that there was <1.0% of 7remaining.

The batch was then distilled under reduced pressure at 45° C. over aperiod of 15 h to afford 4-5 L of a yellow slurry. The batch was thenallowed to cool overnight. Water was added (3 vol) and after heating to45° C., distillation was continued for 1 h until no more distillate wascollected. The vacuum was released and water (3 vol) was added to thebatch. After allowing to settle, the batch was filtered through a slurryof cellulose powder (20 micron, 0.2 wt.) in water (1 vol). Water (2 vol)was added to the remaining solids/slurry in the reactor and this wasfiltered through a sintered glass funnel. This filtrate was then furtherfiltered through the cellulose pad to afforded 11.2 L of productsolution (13.2 vol).

The solution was then transferred to a separatory funnel containingEtOAc (3.3 vol). After stirring and separating, the aqueous phase wastransferred to a 22-L reactor and then a solution of PBu₃ (212 ml, 0.25vol, 97%) in EtOAc (3.5 vol) was charged to the reactor. The solutionwas heated at 50° C. for 2.5 h. Additional EtOAc (3.3 vol) was added tothe reactor and the contents were charged to a separatory funnel and thetwo phases separated. The aqueous phase (41° C.) was charged back to theseparatory funnel and washed with additional EtOAc (3.3 vol). The twophases were separated and then the aqueous phase was charged to a 22-Lreactor and heated to 45° C. Heptane (5 vol) was added to the reactor,the contents of the reactor were transferred to a separatory funnel andthe two phases were separated. The aqueous phase (11.2 L, 13.2 vol) wascharged to the 22-L reactor, diluted to 14 vol with water and then aslurry of Darco G-60 (0.2 wt) in water (1 vol) was charged to thereactor. The mixture was heated to 60° C. and stirred at 60° C. for 2 h.The heat was switched off and the batch was stirred over the weekend.The batch was filtered through a pad of Celpure P300 (0.2 wt, Sigma) andwashed with water (2×1.2 vol).

A 22-L, round-bottom flask equipped with a mechanical stirrer, athermocouple attached to a temperature controller, and pH probe attachedto a pH meter was charged with citric acid (127.5 g, 0.15 wt) and water(2 vol). The solution was heated to 40° C. and the pH of the solutionwas adjusted to 4.0 with a 2 M solution of sodium hydroxide. A solutionof citric acid (40 wt %, 2 L) was charged to an addition funnel and wasattached to the reactor. The basic solution of 8 was then transferredvia peristaltic pump through an in-line filter to the citric acidsolution and the pH was maintained at pH 4.0 with the 40% citric acidsolution. Once the addition was complete, the batch was heated to 60° C.and stirred for 2 h. The batch was then cooled overnight and the solidswere filtered at 29° C. The cake was washed with water (2×2.5 vol) andthen dried at 45-50° C. for 24 h to provide 720 g of 8 (84% yield) witha purity of 85.9% (AUC).

5.13. Optional Purification of(S)-3-(4-(2-Amino-6-chloropyrimidin-4-yl)phenyl)-2-(tert-butoxycarbonylamino)propanoicacid (8)

The crude 8 as prepared from examples 5.11 or 5.12 is impure and usuallycontains about 6% of the diacid impurity (A) and about 4% aminationproduct (B). This material can be used directly in the next step or itcan optional purified by the following methods.

Method 1. To a 3-necked 250 ml RB flask was added crude 8 (10.0 g, 25.4mmol, 90% pure, with 6% A and 4% B), i-PrOH/toluene (1:1, 80 ml/80 ml,8×/8×) and tert-butylamine (13.4 ml, 5.0 equiv). The resulting mixturewas stirred and heated at 78° C. for 1 hour and then slowly cooled to 0°C., and stirred for another hour. The solids were collected byfiltration and the cake was washed with 20 ml of i-PrOH/toluene (1:3).The cake was dried under vacuum to constant weight to provide thedesired tert-butylamine salt of 8 as a pale yellow solid (8.8 g, 74%yield, 94% pure, 3% A, 3% B).

To a 3-necked 250 ml RB flask was added the tert-butylamine salt of 8(20.0 g, 42.9 mmol) and followed by H₂O/THF/toluene (400 ml/200 ml/160ml, 20×/10×/8×). The resulting mixture was heated to 60° C. and slowlyadded 6M HCl until pH of the mixture reached 4.0. The mixture was cooledto room temperature and the organic layer was separated. The organiclayer was washed with H₂O (100 ml, 5×) and concentrated by rotaryevaporating to around 160 ml of overall volume. The solids werecollected by filtration and the cake was washed with 20 ml of toluene.The cake was dried under vacuum to constant weight to provide 8 as apale yellow solid (15.0 g, 89% yield, 94% pure, 3% A, 3% B).

Method 2. To a 3-necked 250 ml RB flask was added crude 8 (20.0 g, 42.9mmol, 90% pure, with 6% A and 4% B) and followed by THF/toluene (200ml/160 ml, 10×/8×). The resulting mixture was heated to 60° C. for 1 hand cooled to room temperature. THF was removed by rotary evaporating toaround 160 ml of overall volume. The solids were collected by filtrationand the cake was washed with 20 ml of toluene. The cake was dried undervacuum to constant weight to provide 8 as a pale yellow solid (11.8 g,70% yield, 92.8% pure, 6.0% A, 1.3% B).

To a 3-necked 250 ml RB flask was added the above 8 (10.0 g, 25.4 mmol)and tert-butylamine (13.4 ml, 5 equiv) followed by i-PrOH/toluene (1:1,80 ml/80 ml, 8×/8×). The resulting mixture was heated to clear (78° C.)for 1 hour, slowly cooled to 0° C., and stirred at 0° C. for another 1hour. The solids were collected by filtration and the cake was washedwith 20 ml of i-PrOH/toluene (1:3). The cake was dried under vacuum toconstant weight to provide the tert-butylamine salt of 8 as a paleyellow solid (9.7 g, 82% yield, 96% pure, 3.3% A, 0.6% B).

To a 3-necked 250 ml RB flask was added the tert-butylamine salt of 8(20.0 g, 42.9 mmol) and followed by H₂O/THF/toluene (400 ml/200 ml/160ml, 20×/10×/8×). The resulting mixture was heated to 60° C. and slowlyadded 6M HCl until pH of the mixture reached 4.0. The mixture was cooledto room temperature and the aqueous layer was separated. The organiclayer was washed with H₂O (100 ml, 5×) and concentrated by rotaryevaporating to around 160 ml of overall volume. The solids werecollected by filtration and the cake was washed with 20 ml of toluene.The cake was dried under vacuum to constant weight to provide 8 as apale yellow solid (15 g, 88% yield, 96% pure, 3.3% A, 0.5% B).

Method 3. To a 3-necked 3 L RB flask was added the aqueous solution ofthe potassium salt containing ˜50 g 8 (90%, 6% A, 4% B, all normalizedAUC) and followed by THF/toluene (500 ml/400 ml, 10×/8×). The resultingmixture was heated to 60° C. and slowly added 6M HCl until pH of themixture reached 4.0. The mixture was cooled to room temperature and theaqueous layer was separated. The organic layer was washed with H₂O (250ml, 5×) and concentrated by rotary evaporating to around 400 ml ofoverall volume to afford a slurry of 8 in ˜8× toluene.

To a 3-necked 3 L RB flask was added the slurry (in 8× toluene, 400 ml)and tert-butylamine (67 ml, 5.0 equiv) followed by i-PrOH (400 ml, 8×).The resulting mixture was heated at 78° C. for 1 hour, cooled to 0° C.,and stirred at 0° C. for another 1 hour. The solids were collected byfiltration and the cake was washed with 100 ml of i-PrOH/toluene (1:3).The cake was dried under vacuum to constant weight to provide thetert-butylamine salt of 8 as a pale yellow solid (42.4 g, 72% yield, 95%pure, 3.2% A, 1.9% B).

To a 3-necked 250 ml RB flask was added the tert-butylamine salt of 8(42.4 g, 91.0 mmol) and followed by H₂O/THF/toluene (1000 ml/500 ml/400ml, 20×/10×/8×). The resulting mixture was heated to 60° C. and slowlyadded 6M HCl until pH reached 4.0. The mixture was cooled to roomtemperature. The organic layer was separated and washed with H₂O (250ml, 5×). The organic solution was concentrated by rotary evaporating to˜400 ml of overall volume. The solids were collected by filtration andthe cake was washed with 100 ml of toluene. The cake was dried undervacuum to constant weight to provide 8 as a pale yellow solid (35.4 g,89.5% yield, 96% pure, 2.9% A, 1.6% B).

Method 4. To a test tube was added 8 (198.6 mg, 0.5 mmol) andcinchonidine (167.1 mg) followed by acetonitrile (7.5 ml). The resultingmixture was heated to clear and cooled to room temperature, and stirredfor another 2 hours. The solids were collected by filtration and thecake was washed with 1 ml of MTBE. The cake was dried under vacuum toconstant weight to provide the final product (208 mg, 68% yield, 92%pure, 4.4% A, 1.4% B).

5.14. Preparation of(S)-3-(4-(2-Amino-6-chloropyrimidin-4-yl)phenyl)-2-(tert-butoxycarbonylamino)propanoicacid (8) using potassium carbonate as base

To a 500 ml 3-neck round-bottom flask equipped with a mechanicalstirrer, a thermocontroller was charged 2-amino-4,6-dichloropyrimidine(12.57 g, 1.5 equiv), boronate compound 7 (20.00 g, 51.1 mmol),potassium carbonate (21.19 g, 3.0 equiv) and ethanol/water (200 ml, 5:1by volume). The mixture was stirred and the catalystbis(triphenylphosphine)palladium(II) dichloride (359 mg, 1 mol %) wasadded. The mixture was heated to 80° C. and stirred for 2 h. Thereaction was cooled to room temperature and diluted with water (100 ml).The mixture was then concentrated under reduced pressure to remove mostof ethanol and 1 N NaOH (60 ml) was added. The mixture was extractedtwice with ethyl acetate (2×200 ml) and the aqueous layer was acidifiedto pH ˜3 using 1 N HCl. The mixture was extracted with ethyl acetatetwice (200 ml and 100 ml, respectively) and the combined organic layerswere concentrated and the residue was purified by column chromatography(gradient 1:20 to 1:10 methanol/dichloromethane) to afford compound 8 asa pale yellow solid (15.92 g, 79%).

5.15. Preparation of(S)-3-(4-(2-Amino-6-chloropyrimidin-4-yl)phenyl)-2-(tert-butoxycarbonylamino)propanoicacid (8) using the lithium salt of(S)-2-(tert-butoxycarbonylamino)-3-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)propanoicacid (7)

During preparation of compound 7, the isolation of the free acid can beoptionally omitted. Thus, an aqueous solution of the lithium salt ofcompound 7 in 100 ml water, prepared from 5.0 g of Boc-Tyr-OMe (4, 17mmol), was mixed 2-amino-4,6-dichloropyrimidine (3.3 g, 1.2 eq),potassium bicarbonate (5.0 g, 3 eq),bis(triphenylphosphine)palladium(II) dichloride (60 mg, 0.5 mol %), and100 ml ethanol. The resulting mixture was heated at 70° C. for 5 h.Additional 2-amino-4,6-dichloropyrimidine (1.1 g, 0.4 eq) was added andheating was continued at 70° C. for 2 h more. HPLC analysis showed about94% conversion. Upon cooling and filtration, the filtrate was analyzedby HPLC against a standard solution of compound 8. The assay indicated3.9 g compound 8 was contained in the solution (59% yield from compound4).

5.16. Alternative Procedure for Preparation of(S)-3-(4-(2-Amino-6-chloropyrimidin-4-yl)phenyl)-2-(tert-butoxycarbonylamino)propanoicacid (8) using potassium carbonate as base

The boronic acid compound 11 (Ryscor Science, Inc., North Carolina, 1.0g, 4.8 mmol) and potassium carbonate (1.32 g, 2 eq) were mixed inaqueous ethanol (15 ml ethanol and 8 ml water). Di-tert-butyldicarbonate(1.25 g, 1.2 eq) was added in one portion. After 30 min agitation atr.t., HPLC analysis showed complete consumption of the starting compound11. The 2-amino-4,6-dichloropyrimidine (1.18 g, 1.5 eq) and the catalystbis(triphenylphosphine)palladium(II) dichloride (34 mg, 1 mol %) wereadded and the resulting mixture was heated at 65-70° C. for 3 h. HPLCanalysis showed complete consumption of compound 12. After concentrationand filtration, HPLC analysis of the resulting aqueous solution againsta standard solution of compound 8 showed 1.26 g compound 8 (67% yield).

5.17. Alternative procedure for preparation of(S)-3-(4-(2-Amino-6-chloropyrimidin-4-yl)phenyl)-2-(tert-butoxycarbonylamino)propanoicacid (8) using potassium carbonate/potassium bicarbonate as base

The boronic acid compound 11 (10 g, 48 mmol) and potassium bicarbonate(14.4 g, 3 eq) were mixed in aqueous ethanol (250 ml ethanol and 50 mlwater). Di-tert-butyldicarbonate (12.5 g, 1.2 eq) was added in oneportion. HPLC analysis indicated that the reaction was not completeafter overnight stirring at r.t. Potassium carbonate (6.6 g, 1.0 eq) andadditional di-tert-butyldicarbonate (3.1 g, 0.3 eq) were added. After2.5 h agitation at r.t., HPLC analysis showed complete consumption ofthe starting compound 11. The 2-amino-4,6-dichloropyrimidine (11.8 g,1.5 eq) and the catalyst bis(triphenylphosphine)-palladium(II)dichloride (0.34 g, 1 mol %) were added and the resulting mixture washeated at 75-80° C. for 2 h. HPLC analysis showed complete consumptionof compound 12. The mixture was concentrated under reduced pressure andfiltered. The filtrate was washed with ethyl acetate (200 ml) anddiluted with 3:1 THF/MTBE (120 ml). This mixture was acidified to pHabout 2.4 by 6 N hydrochloric acid. The organic layer was washed withbrine and concentrated under reduced pressure. The residue wasprecipitated in isopropanol, filtered, and dried at 50° C. under vacuumto give compound 8 as an off-white solid (9.0 g, 48% yield). Purity:92.9% by HPLC analysis. Concentration of the mother liquor yielded andadditional 2.2 g off-white powder (12% yield). Purity: 93.6% by HPLCanalysis.

5.18.(S)-3-(4-(2-Amino-6-((R)-2,2,2-trifluoro-1-(3′-methoxybiphenyl-4-yl)ethoxy)pyrimidin-4-yl)phenyl)-2-(tert-butoxycarbonylamino)propanoicacid

To a 250 ml 3-neck round-bottom flask equipped with a mechanicalstirrer, a thermocontroller was charged monochloride 8 (20.39 g, 51.9mmol), alcohol 3 (17.58 g, 1.2 equiv), cesium carbonate (84.55, 5.0equiv) and dioxane (205 ml). The mixture was heated to 100° C. andstirred for 17 h. The reaction was cooled to room temperature anddiluted with water (80 ml). Two phases were split and the organic layerwas collected and diluted with ethyl acetate (200 ml), washed with amixture of brine (50 ml) and 1 N HCl (50 ml). The organic layer wasconcentrated and the residue was purified by column chromatography(gradient: 1:30 to 1:20 methanol/dichloromethane and 0.5% acetic acid)to afford compound 9 as a yellow solid. This solid was recrystallizedfrom EtOH and heptane to give 21.78 g pale yellow solid. Furthercrystallization of the mother liquor gave 2.00 g pale yellow solid(overall 23.78 g, 72% yield). Chiral analysis of the correspondingmethyl ester derivative, prepared using trimethylsilyldiazomethane,showed no detectable amount of the diastereomers. LC-MS (ESI):MH⁺=639.2. ¹H NMR (DMSO-d₆) δ 12.60 (br s, 1H), 8.00 (d, J=8.0 Hz, 2H),7.77 (d, J=8.0 Hz, 2H), 7.67 (d, J=8.0 Hz, 2H), 7.37 (m, 3H), 7.21 (m,2H), 7.13 (d, J=8.0 Hz, 1H), 6.96 (m, 1H), 6.84 (m, 2H), 6.75 (s, 2H,4.15 (m, 1H), 3.82 (s, 3H), 3.10 (dd, J=13.6, 4.4 Hz, 1H), 2.89 (dd,J=13.6, 10.4 Hz, 1H), 1.32 (s, 9H). ¹³C NMR (DMSO-d₆) δ 173.4, 168.4,166.1, 162.9, 159.7, 155.4, 141.5, 140.8, 134.8, 130.7, 130.0, 129.3,128.4, 127.2, 126.6, 124.1 (q, J=281 Hz), 119.1, 113.4, 112.3, 91.3,78.0, 71.3 (q, J=30 Hz), 55.1, 54.9, 36.2, 28.1. ¹⁹F NMR (DMSO-d₆): δ−74.6 (d, J=7.2 Hz). Anal. Calcd. for C₃₃H₃₃F₃N₄O₆: C, 62.06; H, 5.21;N, 8.77. Found: C, 62.25; H, 5.10; N, 8.69.

5.19. Preparation of(S)-3-(4-(2-Amino-6-((R)-2,2,2-trifluoro-1-(3′-methoxybiphenyl-4-yl)ethoxy)pyrimidin-4-yl)phenyl)-2-(tert-butoxycarbonylamino)propanoicacid under various conditions

Using similar procedure, various reaction conditions were examined. Theresults are listed in the table below.

equiv time % conversion entry of 3 base (x, equiv) additive (h)(isolated yield)^(a) 1 1.2 Cs₂CO₃ (5.0) — 17 97 (72) 2 1.2 NaH (5.0) — 1—^(b) 3 1.2 NaOt-Bu (3.0) — 1 —^(c) 4 1.2 NaOt-Am (3.0) — 1 —^(c) 5 1.2DBU (5.0) — 24  0 6 1.2 tetramethyl- — 24  0 guanidine (5.0) 7 1.2 K₂CO₃(5.0) — 24  0 8 1.2 Cs₂CO₃ (4.0) — 20 98^(d) 9 1.2 Cs₂CO₃ (4.0) 10 mol %17 98^(d) n-Bu₄NHSO₄ 10 1.2 Cs₂CO₃ (3.0) 10 mol % 18 98^(d) n-Bu₄NHSO₄11 1.0 Cs₂CO₃ (3.0) 10 mol % 18 88^(d) n-Bu₄NHSO₄ ^(a)All the reactionswere run in 10x dioxane except otherwise noted; ^(b)The startingmaterial 1 decomposed; ^(c)A complex mixture of starting material, deBocof starting material, product, deBoc of product was observed. ^(d)Thereaction was run in 5x dioxane.

5.20.(S)-2-Amino-3-(4-(2-amino-6-((R)-2,2,2-trifluoro-1-(3′-methoxybiphenyl-4-yl)ethoxy)pyrimidin-4-yl)phenyl)propanoicacid (10)

To a 500 ml round-bottom flask was added compound 9 (20.00 g, 31.32mmol) and THF (100 ml). The solid was dissolved upon stirring and 6 Nhydrochloric acid (100 ml) was added slowly. The mixture was thenstirred at room temperature for 14 h. The reaction was diluted withwater (100 ml) and most of THF was removed under reduce pressure. Theresulting aqueous solution was then transferred to a 500 ml three-neckedround-bottom flask equipped with a mechanical stirrer, a pH meter, athermocontroller and an addition funnel. At 60° C., a solution of 50%aqueous sodium hydroxide was added slowly until pH=4, then a solution of1 N aqueous sodium hydroxide was added until pH reached 6.5. The mixturewas stirred at 60° C. for additional 30 min and the solid was collectedby filtration and oven-dried under vacuum to give compound 10 (16.30 g,96% yield) as a pale yellow solid. LC-MS (ESI): MH⁺=539.1. ¹H NMR(DMSO-d₆) δ 8.01 (d, J=8.0 Hz, 2H), 7.76 (d, J=8.0 Hz, 2H), 7.67 (d,J=8.0 Hz, 2H), 7.38 (m, 3H), 7.23 (m, 2H), 6.96 (d, J=8.0 Hz, 1H), 6.81(m, 3H), 3.81 (s, 3H), 3.59 (br m, 1H), 3.00 (br m, 1H). ¹³C NMR(DMSO-d₆) 169.9, 168.4, 166.1, 162.9, 159.7, 141.5, 140.8, 140.8, 140.0,134.9, 130.7, 130.0, 129.7, 128.4, 127.2, 126.8, 124.1 (q, J=281 Hz),119.1, 113.4, 112.3, 91.2, 71.4 (q, J=30 Hz), 55.1, 55.0, 36.5.

¹⁹F NMR (DMSO-d₆): δ −74.6 (d, J=6.8 Hz).

5.21. One-Pot Preparation of(S)-2-Amino-3-(4-(2-amino-6-((R)-2,2,2-trifluoro-1-(3′-methoxybiphenyl-4-yl)ethoxy)pyrimidin-4-yl)phenyl)propanoicacid (10)

To a 3-neck 250 ml round-bottom flask equipped with a mechanicalstirrer, a thermocontroller, was charged compound 3 (8.62 g, 1.2 equiv),8 (10.00 g, 25.46 mmol), tetrabutylammonium bisulfate (0.86 g, 10 mol%), and cesium carbonate (29.04 g, 3.5 equiv). Dioxane (50 ml) was addedand the resulting mixture was heated at 100° C. for 18 h. HPLC analysisshowed 99% conversion of the starting material 8. The mixture was cooleddown to 60° C. and water (60 ml) was added. The top organic layer wasdiluted with THF (80 ml), washed with brine (50 ml), transferred to a500 ml round-bottom flask, and 80 ml of 6 N hydrochloric acid was added.The mixture was stirred at room temperature for 16 h. LC-MS analysis ofthe reaction mixture showed complete consumption of the intermediatecompound 9. The reaction mixture was transferred to a 500 ml separatoryfunnel. The round-bottom flask was washed with water (2×40 ml) and thewashes were also transferred to the funnel. The mixture was washed withethyl acetate (2×100 ml) and the aqueous layer was collected andconcentrated at 40° C. (bath temperature) under 80 mbar vacuum to removeany remaining organic solvents. The resulting aqueous solution was thentransferred to a 500 ml three-necked round-bottom flask equipped with amechanical stirrer, a pH meter, a thermocontroller and an additionfunnel. At 60° C., a solution of 50% aqueous sodium hydroxide solutionwas added slowly until pH=4, then a solution of 1N aqueous sodiumhydroxide was added until pH reached 6.5. The mixture was stirred at 60°C. for additional 30 min and the yellow solids were collected byfiltration. HPLC analysis of this solid showed a purity of about 95%.The solids were dried under vacuum at 50° C. overnight to give the crudeproduct compound 10 as a yellow solid (9.48 g, 69% overall yield).

The above solids (9.48 g) were transferred to a 500 ml round-bottomflask and water (95 ml) was added. The mixture was heated at 80° C.(bath temperature) and THF (40 ml) was added dissolve the solids. Mostof THF was then removed under vacuum at 80° C. The precipitate was addedacetonitrile (80 ml) and was stirred at 80° C. for 2 h, cooled down tor.t. and then stirred at 0° C. for 30 min. The solid was collected byfiltration, washed with water (2×50 ml) to give compound 10 as a paleyellow solid (8.53 g, 90% recovery, 62% overall yield). HPLC analysisshowed a purity greater than 99%.

5.22. One-pot preparation of(S)-2-Amino-3-(4-(2-amino-6-((R)-2,2,2-trifluoro-1-(3′-methoxybiphenyl-4-yl)ethoxy)pyrimidin-4-yl)phenyl)propanoicacid (10)

A 22-L, round-bottom flask equipped with a mechanical stirrer, athermocouple attached to a temperature controller, and a condenser witha nitrogen line was charged with 1,4-dioxane (4 vol) followed by theaddition of Cs₂CO₃ (2.03 kg, 3.5 equiv), compound 3 (603 g, 1.2 equiv)and tetrabutylammonium bisulfate (102.8 g, 0.147 wt). The slurry wasslowly heated to 70° C. and then a slurry of compound 8 (700.0 g, 1.782mol, 1 wt) in 1,4-dioxane (1.5 vol) was added in three portions over 10min. The beaker containing 8 was rinsed with 1,4-dioxane (0.5 vol) andadded to the reactor. The reaction became thick briefly after stirringfor 15-30 minutes but the entire batch was stirrable. The controller washeated at 78° C. overnight followed by heating at 98° C. for 8 h then85° C. overnight. HPLC analysis indicated that there were 2.1% of 8remaining. The reaction was quenched at 78° C. with water (6 vol) andthen cooled further. At 42° C., the batch was transferred to aseparatory funnel and the two phases separated. The organic phase wasthen diluted with THF (8 vol) and washed with brine (5 vol). The phaseswere separated and the organic phase was washed with brine (5 vol). Thephases were separated and the organic phase (9.5 L) was transferred to a22-L reactor. A solution of 6 N HCl (11.4 vol) was added and the batchwas heated at 40-45° C. for 2 h. HPLC analysis indicated that thereaction was complete and Darco G-60 (0.33 wt.) and water (2 vol) wereadded. The batch was stirred at 40° C. over the weekend and then heatedto 60° C. The reaction mixture was filtered at 60° C. through PTFE clothand the reactor was rinsed with water (6 vol). The rinse was heated to60° C. and washed through the Darco pad. The filtrate was then passedthrough a 0.3-μm in-line filter and washed with IPAc twice (10 vol, 8.8vol). The aqueous phase was then concentrated under reduced pressure at45° C. using a 20-L, rotary evaporator until the mixture turned cloudy(2-3 h). The volume of distillate collected was approximately 3.3 L. Thebatch was then transferred back to a 22-L reactor and held at 40° C.overnight.

The batch was heated to 60° C. whereupon the batch turned from cloudy toclear. To a separate 22-L reactor was charged water (1.6 vol) and 85%phosphoric acid (0.24 vol) and the pH was adjusted to 6.5 using a 50%NaOH solution (approximately 0.3 vol). The acidic product solution wasthen transferred via peristaltic pump to the reactor containing the pH6.5 buffered solution and the pH was maintained within 6 and 7 throughthe addition of 50% NaOH (approximately 3.5 vol). The temperature of thereactor was maintained between 55 and 65° C. (2-h addition time). Oncethe addition was complete, the slurry was heated at 60-65° C. for 90min, filtered, and washed with water (2×6.7 vol). The wet cake was driedin a vacuum oven at 55° C. for 39 h to afford 635 g of crude 10 as ayellow solid (66% yield). The purity of the product was 93.2% (AUC).

5.23. Purification of(S)-2-Amino-3-(4-(2-amino-6-((R)-2,2,2-trifluoro-1-(3′-methoxybiphenyl-4-yl)ethoxy)pyrimidin-4-yl)phenyl)propanoicacid (10)

A 22-L, round-bottom flask equipped with a mechanical stirrer, athermocouple attached to a temperature controller, and a condenser witha nitrogen line was charged with crude 10 (630 g) followed by theaddition of THF (5 vol). The slurry was heated to 65° C. After 30 min, asolution of 5-6 N HCl in IPA (0.47 L, 0.746 vol) was added and thesolids slowly dissolved. The orange solution was heated at 65° C. for 30min IPA (10 vol) was slowly added maintaining the temperature between60-70° C. Once the addition was complete, the mixture was stirred for 20min and then IPAc (10 vol) was slowly added maintaining the temperaturebetween 60-70° C. Once the addition was complete, the thick slurry wasstirred at 65° C. for 1 h and then cooled to 27° C. over 4.5 h. Thesolids were filtered and washed with IPA (2×3 vol). The product wasdried in a vacuum oven at 55° C. for 15 h to afford 630 g of 10 diHClsalt (88% yield) with a purity of 95.0% (AUC).

A 12-L, round-bottom flask equipped with a mechanical stirrer, athermocouple attached to a temperature controller, and a pH probeattached to a pH meter was charged with 10 diHCl salt (620 g, 1 wt)followed by an aqueous solution of 1 M NaOH (10 vol). The mixture washeated to 40° C., stirred until all the solids dissolved (2 h), and thentransferred to a 10-L carboy. The 12-L, round-bottom flask was washedwith water and then 85% phosphoric acid (124 ml, 0.2 vol) and water (1.3vol) were charged to the reactor. The pH was adjusted to 6.5 using 50%NaOH (0.24 vol) and then heated to 65° C. The product solution in thecarboy was transferred via peristaltic pump to the pH buffered solutionand the pH was maintained between 6 and 7 through the addition of anaqueous solution of 6 M HC₁₋₃₉ (0.67 L). Once the addition was complete,the slurry was heated at 65° C. for 3 h and the solids were filtered.The cake was washed with water (3×5 vol) and then dried in a vacuum ovenat 55° C. for 41 h to afford 473 g of 10 as a light yellow solid (87%yield) with a purity of 97.7% (AUC).

All of the publications (e.g., patents and patent applications)disclosed above are incorporated herein by reference in theirentireties.

1. A method of preparing a compound of formula I(a):

which comprises contacting a compound of formula II:

with a compound of formula III:

under conditions sufficient for the formation of the compound of formula I(a), wherein: A is optionally substituted cycloalkyl, aryl, or heterocycle; X is O, S, or NR₆; Y₁ is halogen; P₁ is R₁ or a protecting group; P₂ is a protecting group; P₃ is OR₂, SR₂, NR₉R₁₀, or NHNHR₉; R₁ is hydrogen or optionally substituted alkyl, alkyl-aryl, alkyl-heterocycle, aryl, or heterocycle; R₂ is hydrogen or optionally substituted alkyl, alkyl-aryl, alkyl-heterocycle, aryl, or heterocycle; R₃ is hydrogen, cyano, or optionally substituted alkyl or aryl; R₄ is hydrogen, cyano, or optionally substituted alkyl or aryl; R₆ is hydrogen or optionally substituted alkyl or aryl; R₇ is independently hydrogen, cyano, nitro, halogen, OR₈, NR₉R₁₀, or optionally substituted alkyl, alkyl-aryl or alkyl-heterocycle; each R₈ is independently hydrogen or optionally substituted alkyl, alkyl-aryl or alkyl-heterocycle; each R₉ is independently hydrogen, a protecting group, or optionally substituted alkyl, alkyl-aryl or alkyl-heterocycle; each R₁₀ is independently hydrogen, a protecting group, or optionally substituted alkyl, alkyl-aryl or alkyl-heterocycle; and n is 1-4.
 2. The method of claim 1, wherein the compound of formula II is of formula II(a):

wherein: each R₁₁ is independently hydrogen, cyano, nitro, halogen, OR₈, NR₉R₁₀, or optionally substituted alkyl, alkyl-aryl or alkyl-heterocycle; each R₁₂ is independently hydrogen, cyano, nitro, halogen, OR₈, NR₉R₁₀, or optionally substituted alkyl, alkyl-aryl or alkyl-heterocycle; m is 1-5; and p is 1-4.
 3. The method of claim 2, wherein the compound of formula II(a) is of formula II(b):


4. The method of claim 1, which further comprises deprotecting the compound of formula I(a) to provide a compound of formula I:


5. The method of claim 4, wherein the compound of formula I is of formula I(b):

wherein: each R₁₁ is independently hydrogen, cyano, nitro, halogen, OR₈, NR₉R₁₀, or optionally substituted alkyl, alkyl-aryl or alkyl-heterocycle; each R₁₂ is independently hydrogen, cyano, nitro, halogen, OR₈, NR₉R₁₀, or optionally substituted alkyl, alkyl-aryl or alkyl-heterocycle; m is 1-5; and p is 1-4.
 6. The method of claim 5, wherein the compound of formula I(b) is of formula I(c):


7. The method of claim 6, wherein the compound of formula I(c) is of formula I(d):


8. The method of claim 6, wherein the compound of formula I(d) is of formula I(e):


9. A compound of the formula:

or a salt or solvate thereof, wherein: P₁ is R₁, aryl-alkyl, heteroaryl-alkyl, or —C(O)R₁₃; P₂ is aryl-alkyl, heteroaryl-alkyl, or —C(O)R₁₃; R₁ is hydrogen or optionally substituted alkyl, alkyl-aryl, alkyl-heterocycle, aryl, or heterocycle; and each R₁₃ is independently alkyl, aryl-alkyl, aryl, heterocycle, alkoxy, aryloxy, or aryl-alkoxy.
 10. The compound of claim 9, which is of the formula: 